AI Models · Open-Source vs Paid

Kimi K3.1 Pro Open vs GPT-5.6 Sol Paid

Kimi K3.1 Pro vs GPT-5.6 Sol compared — price per token, context window, multimodality, openness and which to choose. Can the open-source model replace the paid one? Full 2026 breakdown.

Prices & specs refreshed from live data · olud.ai

Open-model prices = cheapest provider via OpenRouter; official maker rates may be higher.

Kimi K3.1 ProOpenMoonshot AI
$2 /M input
$10 /M outputNo per-token fees if you self-host
TypeOpen-weight
Context window1M tokens
MultimodalYes
Self-hostYes
GPT-5.6 SolPaidOpenAI
$4 /M input
$20 /M outputManaged API (no infra to run)
TypeProprietary
Context window1.1M tokens
MultimodalYes
Self-hostNo
Choose Kimi K3.1 Pro if you want to self-host, keep your data private and skip per-token fees — it's open-weight and runs on your own hardware. Choose GPT-5.6 Sol if you want frontier capability through a managed API with zero infrastructure to run.

Kimi K3.1 Pro vs GPT-5.6 Sol specs

SpecKimi K3.1 ProGPT-5.6 SolWinner
MakerMoonshot AIOpenAI–
TypeOpen-weightProprietaryKimi K3.1 Pro
Context window1M tokens1.1M tokensGPT-5.6 Sol
Input price$2/M · free self-host$4/MKimi K3.1 Pro
Output price$10/M · free self-host$20/MKimi K3.1 Pro
Vision / multimodalYesYes= Tie
Tool / function callingYesYes= Tie
Self-hostableYesNo (API only)Kimi K3.1 Pro
LicenseModified MITProprietaryKimi K3.1 Pro

Price gap & when to choose each

2.0×cheaper per output token

Kimi K3.1 Pro is ~2.0× cheaper than GPT-5.6 Sol on output tokens ($10 vs $20 per M tokens).

Choose Kimi K3.1 Pro if…
  • You want to self-host or run on your cloud
  • You prioritize data privacy & control
  • You want the lowest operating costs
  • You are building open or reproducible AI
Choose GPT-5.6 Sol if…
  • You want frontier performance through a managed API
  • You need the longer 1.1M context window
  • You value reliability & ecosystem
  • You don't want to manage infrastructure

Feature comparison

CapabilityKimi K3.1 ProGPT-5.6 Sol
Open weights (downloadable)✓✗
Self-hostable✓✗
Runs fully offline✓✗
Vision / multimodal✓✓
Tool / function calling✓✓
1M+ context window✓✓

Benchmarks: Kimi K3.1 Pro vs GPT-5.6 Sol

Independent benchmark scores measured by Artificial Analysis. Higher is better (except latency).

Kimi K3.1 Pro delivers 2.3× more intelligence per dollar.
Kimi K3.1 Pro
GPT-5.6 Sol
Intelligence index
55.1
47
Humanity's Last Exam
52.5%
49.5%
Long Context Reasoning
86.3%
84%
SciCode
60.8%
57.1%
Coding index
–
77.4
GPQA
–
94.1%
IFBench
–
72.7%
τ²-Bench
–
85.1%
τ-Bench Banking
–
44.3%
Terminal-Bench
–
88%
Terminal-Bench Hard
–
65.9%
Speed
41.2 tok/s
0 tok/s
Latency
2.12s
0s
Intelligence per $
13.8
5.9

Benchmark data by Artificial Analysis.

How Kimi K3.1 Pro and GPT-5.6 Sol score

🏆 Best value & openness: Kimi K3.1 Pro (4.7 vs 3.1 / 5)
CriterionKimi K3.1 ProGPT-5.6 Sol
Cost-efficiency3.53.0
Context window5.05.0
Openness5.01.5
Self-hosting5.01.0
Multimodality5.05.0

Scores come from live data — output price (cost), context length, open vs closed weights (openness & self-hosting) and vision/tool support (multimodality). Raw task quality isn't scored here; it depends on your benchmark — see the verdict.

What each model is

Kimi K3.1 Pro Open

Moonshot AI · Open-weight

Kimi K3.1 Pro is Moonshot AI's flagship open-weight multimodal reasoning model and a post-trained successor to Kimi K3, with a 1M-token context window. It is built for long-horizon coding, 3D...

GPT-5.6 Sol Paid

OpenAI · Proprietary

GPT-5.6 Sol is the flagship model in OpenAI's GPT-5.6 series. It is suited for complex reasoning, coding, and agentic workflows, and is particularly strong at command-line and multi-step coding tasks...

Other models in these families

These variants are tracked but not compared here — one page per family keeps the comparison readable.

Other variants tracked
Kimi K3Kimi K3 (batch)Kimi K2.6Kimi K2.7 CodeKimi K2.5Kimi K2 ThinkingKimi K2 0905Kimi K2 0711

Frequently asked questions

Is Kimi K3.1 Pro as good as GPT-5.6 Sol?

Kimi K3.1 Pro is open-weight and competitive on many tasks, but GPT-5.6 Sol may still lead on the hardest reasoning and agentic work. The gap keeps narrowing — benchmark both on your actual use case before deciding.

Can I run Kimi K3.1 Pro locally?

Yes. Kimi K3.1 Pro has open weights, so you can self-host it on your own GPUs or run it via a low-cost API. GPT-5.6 Sol is API-only and cannot be self-hosted.

How much cheaper is Kimi K3.1 Pro?

Kimi K3.1 Pro costs $10/M output vs $20/M for GPT-5.6 Sol — roughly 2x cheaper via API, and free if you self-host.

Kimi K3.1 Pro vs GPT-5.6 Sol — which should I pick in 2026?

Choose Kimi K3.1 Pro if you want to self-host, keep your data private and skip per-token fees — it's open-weight and runs on your own hardware. Choose GPT-5.6 Sol if you want frontier capability through a managed API with zero infrastructure to run.

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